// 页面添加水印效果

const setWatermark = (str:string)=>{
    const id = '1.23452384164.123412416';
    if(document.getElementById(id) !== null) document.body.removeChild(<HTMLElement>document.getElementById(id));
    const can = document.createElement('canvas');
    can.width = 200;
    can.height = 130;
    const cans:any = can.getContext('2d');
    cans.rotate((-20 * Math.PI) /180);
    cans.font = '12px vedana';
    cans.fillStyle ='rgba(200,200,200,0.30)';
    cans.textBaseline = 'Middle';
	cans.fillText(str, can.width / 10, can.height / 2);
	const div = document.createElement('div');
	div.id = id;
	div.style.pointerEvents = 'none';
	div.style.top = '15px';
	div.style.left = '0px';
	div.style.position = 'fixed';
	div.style.zIndex = '10000000';
	div.style.width = `${document.documentElement.clientWidth}px`;
	div.style.height = `${document.documentElement.clientHeight}px`;
	div.style.background = `url(${can.toDataURL('image/png')}) left top repeat`;
	document.body.appendChild(div);
	return id;

}

// 页面添加水印效果 set 添加水印 del 删除水印

const watermark = {
    set:(str:string)=>{
        let id = setWatermark(str);
        if(document.getElementById(id) === null) id = setWatermark(str);
    },
    del:()=>{
        let id = '1.23452384164.123412416';
		if (document.getElementById(id) !== null) document.body.removeChild(<HTMLElement>document.getElementById(id));
	}
}

export default watermark;